Coal-drill



(Ndllodel.)

G. H. BITTENBENDER.

GOAL DRILL. No. 519,466. Patented May 8, 1894.

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mmlllw d@ Amd NITED STATES PATENT OFFICE.

GEORGE H. BITTENBENDER, OF PLYMOUTH, PENNSYLVANIA.

COAL-DRILL.

SPECIFICATION forming part of Letters Patent No. 519,466, dated May 8, 1894.

Application ined nach 24, 15393..

.To all whom it may concern,.-

Beit known that I, GEORGE H. BITTENBEN- DER, a citizen of the United States, residing at Plymouth, in the county of Luzerne and State 0f Pennsylvania, have invented certain new and useful Improvements in Coal-Drills; and I do hereby declare the following to b'e a full, clear, and exact description of the inventlon, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention has reference to an improvementin bits or independently-constructed cutting points for use with coal drills or other similar boring implements, the object of the invention being to provide adjustable and reverslble cutting devices so arranged in a carrylng head that when they are applied to their work, the gage of incision may be graduated to produce borings of different sizes as may be desired, said cutting Y devices and other parts being readily capable of rearrangement, withdrawal, substitution, and many other changes for the production of diferent actions and functions and the invention therefore consists essentiallyin au independentlyconstructed cutter-head provided with adjustable and reversible cutters operating to accomplish the aforesaid ends and it also consists in the construction,'arrangement and combination of parts,substantially as willpbe hereinafter more fully described and then particularly pointed out in the appended claims.

In the annexed drawings illustrating my invention: Figure 1 is a perspective view of my improved coal drill bit. Fig. 2 is a horizontal section of the same. Fig. 3 is a transverse section.

Similar letters of reference designate corresponding parts in the several figures.

B designates a drill of any ordinary kind, having the usual spiral groove which provides an outlet way for` the refuse material which is cut and broken up by the advancing or working end of the drill. This drill may be of any suitable size and kind and employed for any desired purpose and operated by any kind of machinery.

A designates a cutter-head adapted to be rigidly fixed to the working end of the drill B in lieu of the common integral screw point seriairatemzs. (Nomad.)

with which the end of the old-fashioned drill has been commonly provided. The cutterhead A carries peculiarly-constructed cutting blades or points to be hereinafteraccurately described in detail, the same being adapted to enter into and cut the coal or other substance that is being drilled. This cutterhead A maybe o f any desired size and shape. 1t is. provided at one end with a recess, preferably rectangularly-shaped, although it may be of any desired shape which is adapted to receive a correspondingly shaped projection b, on the end of the drill stem b. A rivet a passes through the endet' the cutter-head A, and the projection b, and thereby the cutterhead is rigidly and immovably secured upon the drill stem. v

The cutter-head A, is provided at its forward end with a ycentrally-located forwardly extending cutter or leading bit C, having a shank c, which enters an opening in the cutter-head, as is clearly shown in Fig. 2 and is firmly secured in said opening by means of the transverse bolt E, which is also employed for the purpose of keeping the lateral cutters in position as will be hereinafter described. The leader bit C obviously is used for the purpose of making the first impression upon the material which is being bored and it cuts out the central portion of the boring, while the other cutters with which the cutter-head is provided, follow atterrit and cut the sides orv wall of the hole. This central bit O can be removed whenever desired for the purpose of sharpening or for permitting the substitution of a new one.

Iwill now describe certain peculiarities in the construction of the cutter head A which clearly distinguish it from anything of the kind now in use. Said cutter head has a wedge shape or tapering construction, its

outer end being larger or of greater diameter thanV its inner end, that is to say, the end which carries the front bit C, is Wider than the endwhich is attached to the drillstem B.

The cutter-head therefore is provided on two opposite sides with inclined or tapering surfaces and these inclined sides are provided with longitudinal recesses A A. These recesses therefore are not parallel to each other, but are inclined, sloping rearwardly inward Se that they are closer to each other at the ICO inner end of the cutter-head A, than at its outer end. These recesses are `not of a dovetailed character, but their edges are rectangular. Furthermore it is to be particularly observed that these recesses A A', have not only a longitudinal inclination as I have sys already described and as is clearly represented in Fig. 2, said inclination being an inclination to the longitudinal axis of the cutter-head, but they also have a transverse inclination as is clearly shown in Fig. 3, the same being an inclination to a transverse axis of the cutter-head. The transverse inclinations of the recesses A A', are preferably of about the same degree, which obviously may vary in different cases. Thus it Will be seen that the cutter-head is provided With laterally-located, doubly-inclined longitudinal recesses A A', and these recesses provide space for the adjustable and reversible blades or knives D D which constitute the eliective cutting mechanism of the bit.

The cutters D D are simply thin flat metallic plates of suitable length and width to permit them to be inserted nicely and accurately into their receiving recesses A A. The opposite ends of the cutters D are provided With cutting points d d which are capable of cutting coal or other material which is being drilled. These cutters D D are therefore similarly constructed at each end so that they are readily reversible. Furthermore they are provided with longitudinal slots D'. Through these slots of the cutters passes the transverse bolt E, already referred to, having on one end ahead E and provided at its other end with the nut e. This bolt When screwed up tightly, holds the two cutters D D firmly in any predetermined position. By removing the bolt, the cutters can be readily taken out of place or reversed or adjusted in position. The long slotsD obviously permit a considerable longitudinal adjustment ot' the cutters D. Since the edges of the receiving recesses A are rectangular and the edges 'of the cutters D which contact with them are likewise rectangular it Will be seen that the cutters may be removed laterally from the recesses Whenever desired and readily replaced therein Without any difliculty or entanglement of the parts. When the cutters D D are located in place in recesses A', it Will be manifest that in consequence of the doubly-inclined character of said recesses, the cutters will occupy doubly-inclined positions, that is to say, they Will be inclined to each other longitudinally and will also have the transverse inclination which is so clearly shown in Fig. 3. When the cutters are in place, their forward cutting points lie opposite to the central bit C. By adjusting the cutters, their forward cutting points can be placed farther from or nearer to the cutterhead. The nearer they are to the cutter-head, the nearer to each other will he the cutting points, consequently the smaller the diameter of the hole Which is being bored. The

farther the forward cutting points d d are placed from the end of the cutter-head, the larger will be the hole which is being bored. Thus it Will be obvious that the gage of iucision of these points may be graduated so as to cut holes of different diameters. It is often necessary in drilling, especiallyin drilling coal, to cut a hole of large diameter and often necessary to cut one of considerably smaller diameter.

My improved bit by reason of the adj ustability of the parts, permits the operator to vary the size of the hole Within considerable limits. This capacity in the bit for cutting a hole of variable size results very clearly from the arrangement of the cutters in the doublyinclined position which I have already de scribed. It desired these cutters maybe situated simply in the longitudinal inclined position, the transverse inclination being omitted. Further it is found in actual practice that good results may be achieved with the employment of a single cutter. Therefore I do not Wish it to be understood that I am obliged in all cases to use both cutters. Also thecutters may be so adjusted that one of the forward cutting points d will be closer to the cutter-head than the other forward cutting point. An example of this is illustrated in Fig. 2. When the cutters are thus arranged, one point will cut on a smaller circle than the other point and it will be found in many cases that this Will be an efficient method of'action resulting in cleavage of the material which is being acted upon.

` Numerous possible uses and novel advantages accruing from the use of a drilling bit constructed as herein described might be mentioned but it is unnecessary as they will be evident to those versed in the practical employment of drills of this character. As already suggested the cutters D D may be at anytime removed and reversed. They can thus be readily taken out for sharpening. Also they will last along time, because having cutting points at each end, when one of the points has been Worn down, the other set of points can be used with equal efficiency.

Many changes in the exact construction, detailed arrangement and precise proportions and form of the several parts of my improved drill bit may obviously be made without departing from the clear intent and scope of the invention and I reserve the liberty of re-constructing and re-arranging and changing the numerous parts so that they may operate to the best advantage and for the attainment of the highest possible degree of ei'liciency.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. The combination with the cutter-head, one or more cutters situated in a recess thereof and at aninclination to the longitudinal axis of the head, said cutter or cutters being adustable and reversible, substantially as speci- IOO 2. 'n combination with `the cutter head', cesses on the sides of the cutter-head,V in the having one or more doubly inclined recesses, manner and for the purpose specified. Io of a cutter or cutters located in said recess or c In testimony whereof I affix my signature in recesses, substantially as described. presence of two witnesses. 5 3. In combination with acutter-head, firmly GEORGE H. BITTENBENDER.

secured to the drill stem,of a central forward Witnesses: v

leading cutter and lateral cutters located ad- E. E. GALLAGHER justably and reversiblyin doubly-inclined rev- GEORGE HECKLES. 

